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From:   Andy Lutomirski <luto@kernel.org>
Date:   Wed, 18 Apr 2018 19:25:27 -0700
Message-ID: <CALCETrUmFfoWE55Nrkiq5cuvPw5oPFJKOg04ky-dJsDVsdSmbg@mail.gmail.com>
Subject: Re: [PATCH v2] prctl: fix compat handling for prctl
To:     Li Bin <huawei.libin@huawei.com>
Cc:     Al Viro <viro@zeniv.linux.org.uk>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        Dominik Brodowski <linux@dominikbrodowski.net>,
        Andrew Morton <akpm@linux-foundation.org>,
        Andy Lutomirski <luto@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Hanjun Guo <guohanjun@huawei.com>
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> On Apr 18, 2018, at 9:06 PM, Li Bin <huawei.libin@huawei.com> wrote:
>
> The member auxv in prctl_mm_map structure which be shared with
> userspace is pointer type, but the kernel supporting COMPAT didn't
> handle it. This patch fix the compat handling for prctl syscall.

I would propose an alternative fix: change the type to u64. As far as
I know, this thing is only used by CRIU, and CRIU doesn’t work (AFAIK)
on native 32-bit anyway.   Do you know of some reason that this
wouldn't work?